• Title/Summary/Keyword: Depletion effect

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Residence Time Effect on the Growth of ZrC by Low Pressure Chemical Vapor Deposition (저압화학기상증착법을 이용한 ZrC 성장에 잔류시간이 미치는 영향)

  • Park, Jong-Hoon;Jung, Choong-Hwan;Kim, Do-Jin;Park, Ji-Yeon
    • Journal of the Korean Ceramic Society
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    • v.45 no.5
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    • pp.280-284
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    • 2008
  • In order to investigate residence time effect on the growth of ZrC film, the ZrC films grew with various system total pressure (P) and total flow rate (Q) by low pressure chemical vapor deposition because residence time is function of system total pressure and total flow rate. Thermodynamic calculations predict that the decomposition of source gases ($ZrCl_4$ and $CH_4$) would be low as increasing the residence time. Thermodynamic calculations results were proved by investigating deposition rate with various residence time. Deposition rate decreased with residence time of source gas increased. Besides, depletion effect accelerated diminution of deposition rate at high residence time. On the other hands, the deposition rated was increased as decreasing the residence time because fast moving of intermediate gas species decrease the depletion effect. The crystal structure was not changed with residence time. However, the largest size of faceted grain showed up to specific residence time and the size of grain was decreased whether residence time increase or not.

Depletion Sensitivity Evaluation of Rhodium and Vanadium Self-Powered Neutron Detector (SPND) using Monte Carlo Method (Monte Carlo 방법을 이용한 로듐 및 바나듐 자발 중성자계측기의 연소에 따른 민감도 평가)

  • CHA, Kyoon Ho;PARK, Young Woo
    • Journal of Sensor Science and Technology
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    • v.25 no.4
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    • pp.264-270
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    • 2016
  • Self-powered neutron detector (SPND) is a sensor to monitor a neutron flux proportional to a reactor power of the nuclear power plants. Since an SPND is usually installed in the reactor core and does not require additional outside power, it generates electrons itself from interaction between neutrons and a neutron-sensitive material called an emitter, such as rhodium and vanadium. This paper presents the simulations of the depletion sensitivity evaluations based on MCNP models of rhodium and vanadium SPNDs and light water reactor fuel assembly. The evaluations include the detail geometries of the detectors and fuel assembly, and the modeling of rhodium and vanadium emitter depletion using MCNP and ORIGEN-S codes, and the realistic energy spectrum of beta rays using BETA-S code. The results of the simulations show that the lifetime of an SPND can be prolonged by using vanadium SPND than rhodium SPND. Also, the methods presented here can be used to analyze a life-time of those SPNDs using various emitter materials.

SOME OUTSTANDING PROBLEMS IN NEUTRON TRANSPORT COMPUTATION

  • Cho, Nam-Zin;Chang, Jong-Hwa
    • Nuclear Engineering and Technology
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    • v.41 no.4
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    • pp.381-390
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    • 2009
  • This article provides selects of outstanding problems in computational neutron transport, with some suggested approaches thereto, as follows: i) ray effect in discrete ordinates method, ii) diffusion synthetic acceleration in strongly heterogeneous problems, iii) method of characteristics extension to three-dimensional geometry, iv) fission source and $k_{eff}$ convergence in Monte Carlo, v) depletion in Monte Carlo, vi) nuclear data evaluation, and vii) uncertainty estimation, including covariance data.

The Depressive Effect of Acupuncture on Dong and Depletion on Fungchi-point (G20) (동자침(洞刺鍼)과 풍지혈(風池穴) 자락(刺絡)의 혈압강하(血壓降下) 효과(效果))

  • Park, In-beohm;Kim, Sang-woo;Kim, Cheol-hong;Seo, Jung-chul;Youn, Hyoun-min;Jang, Kyung-jeon;Song, Choon-ho;Ahn, Chang-beohm
    • Journal of Acupuncture Research
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    • v.20 no.1
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    • pp.13-21
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    • 2003
  • Objective : The aim of this research was to investigate the depressive effect of acupuncture on Dong and depletion on Fungchi-point(G20) in stroke patients. Methods : We measured the blood pressure of the patients who were admitted in the Oriental Medical hospital of Dongeui medical center from 21. Dec. 2001. to 2. Oct. 2002. 41 stroke patients were devided into two groups. 15 patients were treated by acupuncture on Dong. The other 26 patients were treated by depletion on Fungchi-point(G20). The activity of daily living was measured. If systolic blood pressure was over 160 mmHg or diastolic blood pressure was over 90mmHg, acupuncture on Dong and depletion on Fungchi-point(G20) were performed. Then 30 minutes and 60 minutes later, systolic. diastolic blood pressure and pulse rates were measured. Results : After 30 minute of treatment, both acupuncture on Dong and depletion on Fungchi-point(G20) significantly depressed systolic blood pressure and diastolic blood pressure. After 60 minute of treatment, both acupuncture on Dong and depletion on Fungchi-point(G20) were significant in depressing systolic blood pressure and diastolic blood pressure. Pulse rates significantly changed in depletion on Fungchi-point(G20) but did not significantly change in acupuncture on Dong. Conclusions: These results suggest that both acupuncture on Dong and depletion on Fungchi-point(G20) are effective in depressing systolic blood pressure and diastolic blood pressure.

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Compact Model of a pH Sensor with Depletion-Mode Silicon-Nanowire Field-Effect Transistor

  • Yu, Yun Seop
    • JSTS:Journal of Semiconductor Technology and Science
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    • v.14 no.4
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    • pp.451-456
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    • 2014
  • A compact model of a depletion-mode silicon-nanowire (Si-NW) pH sensor is proposed. This drain current model is obtained from the Pao-Sah integral and the continuous charge-based model, which is derived by applying the parabolic potential approximation to the Poisson's equation in the cylindrical coordinate system. The threshold-voltage shift in the drain-current model is obtained by solving the nonlinear Poisson-Boltzmann equation for the electrolyte. The simulation results obtained from the proposed drain-current model for the Si-NW field-effect transistor (SiNWFET) agree well with those of the three-dimensional (3D) device simulation, and those from the Si-NW pH sensor model also agree with the experimental data.

The Tunneling Effect at Semiconductor Interfaces by Hall Measurement (홀측정을 이용한 ZTO 반도체 박막계면에서의 터널링 효과)

  • Oh, Teresa
    • Korean Journal of Materials Research
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    • v.29 no.7
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    • pp.408-411
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    • 2019
  • ZTO/n-Si thin film is produced to investigate tunneling phenomena by interface characteristics by the depletion layer. For diversity of the depletion layer, the thin film of ZTO is heat treated after deposition, and the gpolarization is found to change depending on the heat treatment temperature and capacitance. The higher the heat treatment temperature is, the higher the capacitance is, because more charges are formed, the highest at $150^{\circ}C$. The capacitance decreases at $200^{\circ}C$ ZTO heat treated at $150^{\circ}C$ shows tunneling phenomena, with low non-resistance and reduced charge concentration. When the carrier concentration is low and the resistance is low, the depletion layer has an increased potential barrier, which results in a tunneling phenomenon, which results in an increase in current. However, the ZTO thin film with high charge or high resistance shows a Schottky junction feature. The reason for the great capacitance increase is the increased current due to tunneling in the depletion layer.

Effect of Dietary Taurine on Free Amino Acid Concentrations in Blood and Various Tissues of Cats (식이 내의 타우린 함량이 고양이의 혈액 및 주유조직의 유리 아미노산 농도에 미치는 영향)

  • 박태선
    • Journal of Nutrition and Health
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    • v.28 no.9
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    • pp.846-854
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    • 1995
  • Taurine concentrations in blood and various tissues were measured in cats fed normal trurine diet(0.15% taurine) and trurine-free diet(0% taurine) for 5 weeks and 12 weeks, respectively. Cumulative body weight gain in young cats fed normal taurine diet and taurine-free diet for the initial 5 weeks were 463$\pm$43g and 383$\pm$53g respectively. Taurine concentration was one to two orders magnitude higher in most tissues than in plasma, among which the liver taurine-free diet for 12 weeks resulted in 98% reduction in plasma taurine concentration, 93% reduction in whole blood tarurine concentration, and 40~90% reduction in tissue taurine concentrations compared to the values for normal taurine diet group. Among the tissues tested, taurine depletion was most profound in heart and kidney, while liver and intestine were relatively resistant to taurine depletion. Whole blood taruined concentration appeared to be a better index for the body taurine status of cats as in more closely reflects the rate of taurine depletion in tissues. Taurine depletion in cats significantly increased the concentrations of essential and non-essential free amino acids in liver, while free amino acid concentrations in other tissues were not affected by taurine depletion.

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Evaluation of Stream Depletion from Groundwater Pumping in Deep Aquifer Using An Analytical Model (해석적 모형을 이용한 심부대수층 지하수 양수로 인한 하천수 감소량 분석)

  • Lee, Jeongwoo;Chung, Il-Moon;Kim, Nam Won
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.36 no.5
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    • pp.769-777
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    • 2016
  • The objective of this study was to evaluate the stream depletion from groundwater pumping in deep aquifer using the Ward and Lough's analytical solution (2011) which considers a two-layer leaky aquifer system. The calculated results for each pumping from the 110 wells beside streams showed a wide range of non-dimensional stream depletion, that is the streamflow depletion rate divided by the groundwater pumping rate, from lower than 0.1 to more than 0.9 on average for 5 years depending on the specific properties of well location. From the comparison with Hunt's solution (1999) of a single layer aquifer, the Ward and Lough's solution showed about 50% lower than the Hunt's solution due to the difference of hydraulic properties between the first and second layers as well as the lagged effect of vertical leakance. It was also found that the groundwater pumping has a minor effect on the stream depletion if the stream depletion factor (SDF) of the 1st layer is higher than about 1,000 or the SDF of the 2nd layer is higher than about 100, or the vertical leakance is smaller than $10^{-5}s^{-1}$. Furthermore, in the present study, the variations of the stream depletion were assessed according to the magnitude of unmeasured hydraulic properties such as transmissivity and storage coefficient of the 1st layer, vertical hydraulic conductivity of the 2nd layer, the streambed hydraulic conductance.

A Study on the Effects of Workplace Bullying on Emotional Depletion and Organizational Commitment-The Role of Social Support (직장 내 괴롭힘이 정서적 고갈 및 조직몰입에 미치는 영향에 관한 연구 - 사회적 지원의 역할)

  • Jeong, Hae Suk;Kim, Hyun;Hyeon, Byung Hwan
    • The Journal of the Korea Contents Association
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    • v.21 no.12
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    • pp.463-476
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    • 2021
  • This study examined significant differences in the impact of workplace bullying on emotional depletion and organizational commitment, and used 400 questionnaires to examine whether there would be significant differences depending on social support. As an analysis method, we used SPSS 24 for sample characteristics, SmartPLS 3 statistical programs for verifiable factor analysis, reliability and validity, path analysis, and structural equation models. Studies have shown that bullying in the workplace affects significant positive (+) for emotional depletion, and that emotional depletion affects significant negative (-) for tissue commitment. The influence relationship between workplace bullying and tissue commitment was partially mediated in the direction of wealth (-), and the effect of emotional depletion on tissue immersion was shown to be significant differences in the control of social support. Implications are that bullying in the workplace affects emotional depletion, so corporate efforts to prevent bullying are urgently needed, suggesting that employees can improve their organizational commitment, by using a system or community that can promote communication with their bosses.

Effect of trimethyl-indium source depletion on InGaAsP epilayer grown by MOCVD (Trimethyl-indium 소스 고갈에 따른 InGaAsP 에피층의 특성 변화)

  • 김현수;오대곤;편광의;최인훈
    • Journal of the Korean Vacuum Society
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    • v.9 no.4
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    • pp.400-405
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    • 2000
  • We investigated the effect of TMIn (trimethly-indium) source depletion on InGaAs, InGaAsP and 1.55 $\mu\textrm{m}$ InGaAs/InGaAsP SMQW by using EPISON ultrasonic monitor for measuring the concentration of metalorganic/carrier gas mixtures. And the problems for the growth reproducibility in MOCVD was solved by using an EPISON ultrasonic monitor with closed-loop mode under the condition of TMIn source depletion. The saturation pressure of TMIn was dramatically decreased over consumption of 80%. In the case of bulk epilayer, Up-shifting of 300 arcsec to Ga-rich direction and FWHM broadening by a factor of two in DCXRD spectrum were observed due to the TMIn source depletion. In the case of SMQW, Up-shifting of 300 arcsec to Ga-rich direction in DCXRD spectrum and blue-shift of 40 nm in PL spectrum were observed due to the TMIn source depletion. However, good reproducibility ($\Delta\theta$<$\pm$100 arcsec) was achieved even the condition of 95% of TMIn consumption, when we used the EPISON with closed-loop mode.

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